Comet Hale–Bopp (formally designatitC/1995 O1) wis perhaps the maist widely observed comet o the 20t century an ane o the brichtest seen for mony decades. It wis visible tae the naked ee for a record 18 months, twice as lang as the previous record haulder, the Great Comet o 1811.

Hale–Bopp wis discovered on Julie 23, 1995, at a great distance frae the Sun, raisin expectations that the comet would brichten considerably bi the time it passed close tae Yird. Altho predictin the brichtness o comets wi ony degree o accuracy is very difficult, Hale–Bopp met or exceedit maist predictions when it passed perihelion on Aprile 1, 1997. The comet wis dubbed the Great Comet o 1997.